Sealants are found in many different forms. Sealants can be a stand-alone product capable of securing two objects together or can be embedded within a substrate to secure two sides of a package together. For example, many laminated products include a heat seal around one or more edges of the product. The seal is effected by applying heat and/or pressure to multiple films and causing mechanical bonding between two or more of the films.
Sealants are also commonly used in tamper-evident packages. Tamper-evident packages are used in a variety of fields to determine whether a package has been opened or otherwise tampered with. For example, the medical industry uses tamper-evident packaging to show when a sterile package has been opened and exposed to a non-sterile atmosphere, at times compromising the safe use of the contents of the package.
Current tamper-evident packaging does not provide strong visual evidence that the seal has been opened. Conventional medical packaging generally only displays an indicator that does not change the color of the film from which it originated. In the event that the user (such as a doctor, nurse, or other medical professional) is not aware that the seal has been opened, the contents of the package may be used in an unsafe manner.
In addition, the colorless or mono-colored film provides no marketing advantages, and counterfeiters can easily replicate the package due to its visual simplicity.